class_docstr: Tests for core matrix
docstr: Test that core_matrix returns the correct matrix when no differentiable parameter is
  used.
docstr_tok: ["Test","that","core_matrix","returns","the","correct","matrix","when","no","differentiable","parameter","is","used","."]
code: def test_core_matrix_nodiff(self, symbols, geometry, c_ref):
      r"""Test that core_matrix returns the correct matrix when no differentiable parameter is
      used."""
      mol = qchem.Molecule(symbols, geometry)
      c = qchem.core_matrix(
          mol.basis_set, mol.nuclear_charges, mol.coordinates
      )()
      assert np.allclose(c, c_ref)
  
imports: import pytest
  import pennylane
  from pennylane import numpy
  from pennylane import qchem
label_desc: Use image node_id 2 for calling the TestCoreMat obj's underlying member method code with example usage: obj.test_core_matrix_nodiff(symbols, geometry, c_ref) without return types